Process of internally refinishing hollow shells



-June16,1942. FJ. LANGV 2,287,000

PROCESS OF INTERNALLYAREFINISHING HOLLOW SHELLS Filed Aug. 2, 1940l L uw INVENTOR 6PM/Af J Awe I ATTORNEY Patented June 16, 1942 NETE@ STATES PATENT GFHCE Paocsss or INTERNALLXREFI'NISHING HOLLOW sHELLs 3 Claims.

This invention relates to new and useful improvements in grinding processes and particularly seeks to provide a novel method of renishing the internal surfaces of hollow rotary cylinders such as suction couch rolls used in papermaking machines or the like.

Heretofore when the internal surfaces of suction couch rolls, or other hollow rotary cylinders which are backed internally by stationary packing strips, have become grooved or otherwise irregular from uneven wear, it has been necessary to completely remove such rolls from the machine with which they are associated and reinish the same with special jigs and machinery for internally grinding cylindrical surfaces. This procedure has been found to be both costly and timeconsuming since special equipment had to be employed in the refinishing ofthe cylinders and the machines from which the cylinders were removed had to be shut down for relatively long periods of time.

This invention completely eliminates the need for special equipment and provides a novel method of internally grinding and renishing hollow rotary cylinders while such cylinders are maintained in normal operative position on the machine with which they are associated.

Therefore, an object of this invention is to provide a method of renishing the internal surfaces of hollow rotary cylinders while the same are operatively connected to the machine with which they are associated.

Another object of this invention is to provide a method of refinishing internal surfaces of such types of hollow rotary cylinders as have axially disposed stationary packing strips normally maintained in Contact with the moving surface of a cylinder.

Another object of the invention is to provide a method of the character stated which includes the step of maintaining stationary blocks of abrasive material in pressure contact with the surface areas of a cylinder to be refinished While the cylinder is operatively connected in the normal manner to the machine with which it is associated.

Another object of the invention is to provide a method of the character stated which comprises removing the stationary packing Strips from their support and replacing the same with abrasive blocks of similar size, then operating the cylinder in a normal manner whereby sliding contact between the abrasive blocks and the cylinder surface associated therewith will effect the refinishing of said surface, and finally removing said abrasive blocks and restoringthe packing strips to the support with which they are ncrmally associated.

Another object of this invention is to provide a method of the character stated in which the cylinder is shifted axially at periodic intervals of time during the rotation thereof whereby the formation of grooves in the surface being renished will be prevented.

With these and other objects in View, the nature of which will be more apparent, the invention will be more fully understood by reference to the draw-ing, the accompanying detailed description, and the appended claims.

In the drawing:

Fig. 1 is a side elevation, partly in section, of a typical suction couch roll upon which the method embodied in this invention may be practiced;

Fig. 2` is an end elevation thereof;

Fig. 3 is a vertical transverse section taken on line 3 3 of Fig. 1 and Fig. 4 is ya vertical transverse section taken on the line 3 3 of Fig. l showing the abrasive blocks in position.

In order that the method in which this invention is embodied may be more easily understood, a brief description of the suction couch roll assembly will be made, although it is to be understood that this method 'of renishing the internal surfaces of hollow rotary cylinders may be employed with any other mechanisms employing analogous operating mechanical parts.

Referring to the drawing in detail, the suction couch roll assembly includes an open-ended cylindrical shell 5 having a plurality of perforations 6 formed therein. The shell 5 is journalled at its ends in bearing mounts l and 8, respectively, the bearing mount 'l being an idle bearing and the bearing mount 8 being associated with power drive connections for rotating the shell (not shown) and contained in a housing generally indicated at 9. Each of the bearing mounts 1 and 8 carries a vertically disposed yoke II) having an upper cross bar Il and a lower cross bar I2 adapted to support a suction box or manifold I3 at its end. The center portion of the top of the manifold is provided with a longitudinal slot I4 through which fluids are adapted to be drawn. One end of the manifold I3 is closed as by a plate I5 and the other end is connected to a vacuum pump (not shown) through a pipe or flexible conduit I6.

Fluids are adapted to be drawn through the perforations 6 in the shell by the manifold and the vacuum connected therewith, and in order that this action may be confined to a predetermined area of the shell, the manifoldis provided with a pair of upwardly diverging longitudinally exten-ded channels I'I, I'I which support removably mounted packing strips I8 effective to form a seal between the manifold and the rotating shell 5.

The manifold I3 is resiliently supported by the lower cross bars I2 of the yokes I0 through the medium of compression springs I9 carried by posts 2U and extending between the cross bars and the bottom of the manifold. The posts 29 may be vertically adjusted to vary the compressive force exerted by the springs through the medium of adjusting screws 2 I. Thus the manifold is urged upwardly towards contact with the shell and the packing strips I8 are maintained in pressure contact with the internal surface of the shell. Excessive pressure contact between the packing strips and the shell is avoided through the use of downwardly extending screws 22 adjustably carried by the upper cross bars II and effective to properly limit the upward movement of the manifold under infiuence of the springs I9.

When the shell is rotated by means of the driving mechanism 9 the internal surface thereof slides across the faces of the packing strips I8. Continued rotation of the shell for long periods of time is likely to result in unequal wearing of both the shell and the packing strips. Such unequal wearing forms groove in theshell which naturally increase the areas of surface contact between the shell and the packing strips and requires added power to rotate the shell with a resultant decrease in the overall efficiency. If the shell were to be shifted axially in an attempt to counteract the uneven wearing of the parts, the grooves worn therein would become misaligned with the corresponding portions of the packing strips and a further decrease in overall efciency would result since a multitude of irregularly shaped orifices would be formed which would permit leakage. Thus when the internal surface of the shell becomes irregularly worn it must be renished as by grinding.

The method of grinding the shells as embodied in this invention permits the internal surfaces of the shells to be renished in situ without the necessity of special jigs or tools. When a shell is to be reground the operators of the machine with which the shell is associated first remove the manifold I3 by backing off the compression spring adjusting screws 2| and by raising the limiting screws 22, then moving the manifold axially through the shell until the channel I1 and the packing strips I8 mounted thereon are fully exposed. The packing strips are removed from the channel il and replaced by abrasive blocks ISA of similar size and shape and which are preferably formed from carborundum or other abrasive material possessing similar characteristics. The manifold with the abrasive blocks installed thereon is then returned to its normal operative position within the shell as shown in Fig. 4.

After the manifold has again been set up within the shell, the shell is rotated in its normal operative manner through the driving connections 9 without ever having been removed from the papermaking machine. It is readily apparent that relative sliding contact between the internal surface of the shell and the abrasive blocks IEA carried by the channels Il will effect a grinding or abrading of the shell, and a smooth finish will result.

The grinding pressure between the abrasive blocks and the shell may be accurately regulated by the compression spring adjusting screws 2|, and the rate of grinding may be varied accordingly. The depth of cut of grinding is regulated by the limiting screws 22 which may be positioned to permit a continuous grinding of the shell to the desired depth or may be periodically positioned to progressively increase the depths of cut until the total desired depth of cut has been reached.

Normally it will not be necessary to employ added fluids to lubricate the abrasive blocks to prevent loading thereof during the grinding of the shell, but it may become necessary to do so at certain times or when refinishing other types of hollow cylinders. The lubrication of the abrasive blocks to prevent loading may be effected either through the use of water or kerosene.

At periodic intervals during the grinding operation the manifold should be shifted axially a short distance in order to prevent the abrasive blocks from wearing unevenly; otherwise the grinding itself would continue the formation of grooves or would form new grooves in the shell.

After the grinding has been carried to the desired depth of cut the rotation of the shell is stopped, the manifold is again removed and the abrasive blocks are replaced by new packing strips and the manifold is returned to its normal position within the shell.

It should be noted that by employing this method of grinding suction couch rolls the actual periods of shut-down 'of machine operation are reduced to only the two short time intervals during which the packing strips and abrasive blocks are interchanged. At all other times the machine with which the shell is associated is operated in the normal manner.

Thus it will be seen that the herein disclosed invention provides a novel method of refinishing the internal surfaces of suction couch rolls in situ on the machines with which they are associated and which includes the step of maintaining stationary blocks of abrasive material in pressure contact with the surface areas of a roll to be reiinished.

It is of course to be understood that certain details of arrangement and proportions of parts may be variously modified without exceeding the scope of the appended claims.

I claim:

l. The method of refinishing in situ the internal surfaces of hollow rotary cylinders which are backed internally by stationary packing strips, which comprises removing the packing strips from their support and replacing the same with abrasive blocks of similar size, then operating the cylinder in a normal manner whereby sliding contact between the abrasive blocks and the cylinder surface associated therewith will effect the renishing of said surface, and finally removing said abrasive blocks and restoring said packing strips tothe support with which they are normally associated.

2. The method of refinishing in situ the internal surfaces of suction couch rolls having longitudinally disposed suction boxes located therein and including packing strips mounted thereon and disposed in sliding contact with the internal surface of the roll, which comprises removing the packing strips from said suction box and replacing the same with abrasive blocks of similar size then operating the roll in a normal manner` whereby sliding contact between the abrasive blocks and the internal roll surface associated therewith will effect the refinishing of said surface, and finally removing said abrasive blocks and restoring said packing strips to the suction box with which they are normally associated.

3. The method of renishing in situ the internal surfaces of suction couch rolls having longitudinally disposed suction boxes located therein and including packing strips mounted thereon and disposed in sliding contact with the internal surface of the roll, which comprises removing the packing strips from said suction box and replacing the same With abrasive blocks of similar size,

then operating the roll in a normal manner whereby sliding contact between the abrasive blocks and the internal roll surface associated therewith will effect the refinishing of said surface, shifting said roll a short distance axially at periodic intervals of time whereby grooving of the surface being refnished will be avoided, and nally removing said abrasive blocks and restoring said packing strips to the suction box with 10 which they are normally associated.

FRANK J. LANG. 

